Reduce memory cost in entry_table

Original code double entry table space if there is no space. It may
waste 50% memory of the entry table. Now we use a link list to store
entry items.

diff --git a/assembler/src/main.c b/assembler/src/main.c
index 1da9fe7..49f201c 100644 (file)
--- a/assembler/src/main.c
+++ b/assembler/src/main.c
@@ -116,47 +116,27 @@ static void free_register_table(void)
     }
 }
 
-char **entry_point_table = NULL;
-int entry_point_table_length = 0;
+struct entry_point_item {
+       char *str;
+       struct entry_point_item *next;
+} *entry_point_table;
 
-#define DEFAULTBUFSIZE 800
 static int read_entry_file(char *fn)
 {
        FILE *entry_table_file;
-       char buf[DEFAULTBUFSIZE];
-       char *ptr;
-       int curr_table_length = 80;
-       if (!fn) {
+       char buf[2048];
+       struct entry_point_item **p = &entry_point_table;
+       if (!fn)
                return 0;
-       }
-       if ((entry_point_table = 
-                       malloc(curr_table_length*sizeof(char*))) == NULL) {
-               return 1;
-       }
-       
-       entry_table_file = fopen(fn, "r");
-       if (!entry_table_file) {
-               return 1;
-       }
-       
-       while (1) {
-               int size = DEFAULTBUFSIZE;
-               if((ptr = fgets(buf, size, entry_table_file))==NULL)
-               {
-                       break;
-               }
-               buf[strlen(buf)-1] = '\0';
-               if(entry_point_table_length == curr_table_length)
-               {
-                       if ((entry_point_table = realloc(entry_point_table, 
-                                       curr_table_length*2*sizeof(char*))) == NULL) {
-                               return 1;
-                       }
-                       curr_table_length *= 2;
-               }
-               entry_point_table[entry_point_table_length] = strdup(buf);
-               entry_point_table_length ++;
-               
+       if ((entry_table_file = fopen(fn, "r")) == NULL)
+               return -1;
+       while (fgets(buf, sizeof(buf)-1, entry_table_file) != NULL) {
+               // drop the final char '\n'
+               if(buf[strlen(buf)-1] == '\n')
+                       buf[strlen(buf)-1] = 0;
+               *p = calloc(1, sizeof(struct entry_point_item));
+               (*p)->str = strdup(buf);
+               p = &((*p)->next);
        }
        fclose(entry_table_file);
        return 0;
@@ -164,15 +144,22 @@ static int read_entry_file(char *fn)
 
 static int is_entry_point(char *s)
 {
-       int i;
-       for (i = 0; i < entry_point_table_length; i++) {
-           if (strcmp(entry_point_table[i], s) == 0) {
+       struct entry_point_item *p;
+       for (p = entry_point_table; p; p = p->next) {
+           if (strcmp(p->str, s) == 0)
                return 1;
-           }
        }
        return 0;
 }
 
+static void free_entry_point_table(struct entry_point_item *p) {
+       if (p) {
+               free_entry_point_table(p->next);
+               free(p->str);
+               free(p);
+       }
+}
+
 static void
 print_instruction(FILE *output, struct brw_program_instruction *entry)
 {
@@ -379,6 +366,7 @@ int main(int argc, char **argv)
        if (binary_like_output)
                fprintf(output, "};");
 
+       free_entry_point_table(entry_point_table);
        free_register_table();
        fflush (output);
        if (ferror (output)) {